This week, NASA released images of the first cloud map of any planet beyond our solar system. The planet, known as Kepler-7b, is one of more than 150 exoplanets discovered by the Kepler telescope, and lies about 1,000 light years away from Earth.

The news follows a study of the exoplanet, more than three years in the making, which utilized data from both the Kepler and Spitzer space telescopes. In its latest findings, published in this month’s Astrophysical Journal Letters, researchers have produced a low-resolution map that depicts “a remarkably stable climate” on Kepler-7b, according to Thomas Barclay from NASA’s Ames Research Center. Rather than frequently shifting cloud patterns, like those found on Earth, scientists believe the exoplanet has consistently clear skies in the east and high cloud coverage in the west.

Scientists first began looking into the planet’s climate after the Kepler telescope picked up an anomaly on the planet’s western hemisphere. Unable to determine whether the bright spot they were seeing was a heat spot on the planet or cloud coverage above it, they called in the Spitzer telescope to get an accurate reading of the planet’s atmosphere. Spitzer, capable of detecting infrared light, allowed NASA to get its first temperature readings of Kepler-7b, estimated to be between 1,500 and 1,800 degrees Fahrenheit.

That’s certainly hot—but not nearly as hot as NASA would have expected, given the planet’s close proximity to its own star, far closer than the Earth is to the Sun. With a heat spot ruled out, the team was able to confirm that the western half of the planet experiences nearly continuous cloud coverage; clouds which are reflecting back much more light that most other planets of a comparable size.

This isn’t the first peculiarity scientists have discovered about Kepler-7b. They had already determined that the planet is 1.5 times the size of Jupiter—but only has half that planet’s mass—leading NASA to dub Keplar-7b one of the “puffiest” planets ever discovered. Its low mass allows the planet to whip around its star at a dizzying speed—a year on Keplar-7b lasts less than five days—and if the planet could be placed into a massive intergalactic bathtub, it would float.

The Keplar mission was launched in March 2009, and Kepler-7b was one of the first exoplanets it discovered. Since then, it has helped NASA identify more than 150 exoplanets, including one of the darkest planets yet discovered (Kepler-1b), as well as one of the smallest (Kepler-37b). In April of 2013, NASA announced the discovery of three Earth-like “water worlds” in the Lyra constellation, more than 1,2000 light years away, that fall into the category of “Goldilocks” planets, where conditions may be “just right” to support life.

Just weeks later, however, a malfunction with the Kepler telescope’s reaction wheels, which help focus its fixed field of view towards planetary bodies, caused a cessation in the collection of scientific data. After a failed attempt at fixing the two wheels, NASA remains uncertain about the mission’s fate, which was due to last until 2016. The Spitzer telescope, crucial to the latest discovery about Kepler-7b, is itself operating at partial capacity. First launched in 2003 with a mission length of 2.5 years, it more than doubled that before its onboard liquid helium supply ran out in 2009, rendering all but its infrared technology no longer usable.

Astronomers have discovered a lonely planet that doesn’t orbit a star, according to a new report from the Institute for Astronomy at the University of Hawaii at Manoa. The orphaned planet, known as PSO J318.5-22, is six times the mass of Jupiter and is located just 80 light-years from Earth. “We have never before seen an object free-floating in space that that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” said the IfA’s Dr. Michael Liu in a press release, “I had often wondered if such solitary objects exist, and now we know they do.”

PSO J318.5-22 was discovered during a search for brown dwarfs, or failed stars. The orphaned planet’s heat signature stood out when observed by astronomers using the Pan-STARRS 1 wide-field survey telescope on Haleakala, Maui. During follow-up observations, the team determined that PSO J318.5-22 likely belongs to the Beta Pictoris moving group of stars that formed about 12 million years ago.

“Planets found by direct imaging are incredibly hard to study, since they are right next to their much brighter host stars. PSO J318.5-22 is not orbiting a star so it will be much easier for us to study. It is going to provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth,” said study co-author Dr. Niall Deacon of the Max Planck Institute for Astronomy in Germany.

Astronomers have discovered a lonely planet that doesn’t orbit a star, according to a new report from the Institute for Astronomy at the University of Hawaii at Manoa. The orphaned planet, known as PSO J318.5-22, is six times the mass of Jupiter and is located just 80 light-years from Earth. “We have never before seen an object free-floating in space that that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” said the IfA’s Dr. Michael Liu in a press release, “I had often wondered if such solitary objects exist, and now we know they do.”

PSO J318.5-22 was discovered during a search for brown dwarfs, or failed stars. The orphaned planet’s heat signature stood out when observed by astronomers using the Pan-STARRS 1 wide-field survey telescope on Haleakala, Maui. During follow-up observations, the team determined that PSO J318.5-22 likely belongs to the Beta Pictoris moving group of stars that formed about 12 million years ago.

“Planets found by direct imaging are incredibly hard to study, since they are right next to their much brighter host stars. PSO J318.5-22 is not orbiting a star so it will be much easier for us to study. It is going to provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth,” said study co-author Dr. Niall Deacon of the Max Planck Institute for Astronomy in Germany.

dude, they just found the fucking Death Star. Evidently rhe rebels didnt destroy it yet. Quick, lets go hijack it!

One in five Milky Way stars hosts potentially life-friendly Earths: study

One out of every five sun-like stars in the Milky Way galaxy has a planet about the size of Earth that is properly positioned for water, a key ingredient for life, a study released on Monday showed.

The analysis, based on three years of data collected by NASA's now-idled Kepler space telescope, indicates the galaxy is home to 10 billion potentially habitable worlds.

The number grows exponentially if the count also includes planets circling cooler red dwarf stars, the most common type of star in the galaxy.

"Planets seem to be the rule rather than exception," study leader Erik Petigura, an astronomy graduate student at the University of California at Berkeley, said during a conference call with reporters on Monday.

Petigura wrote his own software program to analyze the space telescope's results and found 10 planets one- to two-times the diameter of Earth circling parent stars at the right distances for liquid surface water.

The telescope worked by finding slight dips in the amount of light coming from target stars in the constellation Cygnus.

Some light dips were due to orbiting planets passing in front of their parent stars, relative to Kepler's line of sight.

Extrapolating from 34 months of Kepler observations, Petigura and colleagues found that 22 percent of 50 billion sun-like stars in the galaxy should have planets roughly the size of Earth suitably positioned for water.

A positioning system problem sidelined Kepler in May. Scientists are developing alternative missions for the telescope. More than a year of data already collected by Kepler, which was launched in 2009, still has to be analyzed.

In another Kepler study, the telescope found 3,538 candidate planets, 647 of which are about the size of Earth, said astronomer Jason Rowe, with the SETI Institute in Mountain View, California.

Of the 3,538 candidates, 104 are at the right distance from their parent stars for water, he said.

"When exoplanet hunting started, everyone expected solar systems to look just like ours," Rowe said. "But we're finding quite the opposite, that there's a wide variety of systems out there. If you can imagine it, the universe probably makes it."

The research was published in this week's Proceedings of the National Academy of Sciences and presented on Monday at a Kepler science conference at NASA's Ames Research Center in Moffett Field, California.

Astronomers announced this week that they have spotted a rocky Earth-size planet beyond our solar system, the smallest alien world accurately sized by observers to date. However, the super-hot planet is no second Earth, and according to theories, the distant world some 700 light-years away from Earth shouldn’t exist.

The planet, Kepler-78b, was first discovered by its namesake NASA space telescope. The planet is about 20 percent larger than the Earth, with a diameter of 9,200 miles, and it weighs almost twice as much.

Using the world’s largest ground-based telescopes, two independent research teams have now confirmed the planet’s mass and density by measuring “wobbles” of its sun-like host star, seen as the exoplanet orbits around it. They report the confirmations in the journal Nature.

Unfortunately, Kepler-78b is not Earth 2.0, however, because it turns out that it circles its star at a scorching distance of one million miles. A year on this fast-paced little world lasts only 8.5 hours.

“It’s Earth-like in the sense that it’s about the same size and mass, but of course it’s extremely unlike the Earth in that it’s at least 2,000 degrees hotter,” says co-author Josh Winn, an astronomer at MIT.

“It’s a step along the way of studying truly Earth-like planets.”

The problem astronomers have with their finding is that according to what we understand about planet formation, this hot lava world couldn’t have formed so close to its star, nor could it have moved there.

“This planet is a complete mystery,” says study co-author David Latham, an astronomer at the Harvard-Smithsonian Center for Astrophysics. “We don’t know how it formed or how it got to where it is today. What we do know is that it’s not going to last forever.”

Astronomers have a quandary on their hands. They don’t believe the planet could have formed in its current orbit because then Kepler-78b would have been inside the much larger, younger star. At the same time, it couldn’t have formed farther out and migrated inward, because it should have been drawn on a swirling kamikaze dive straight into the star.

“How it came to reside in its current 8.5-hour orbit is uncertain,” says planetary scientist Drake Deming of the University of Maryland in a commentary accompanying the studies. “Among the more exotic possibilities is that it is the remnant core of a disrupted gas giant,” he writes.

Because it has the tightest orbit around a star ever seen, one thing researchers know for sure is that Kepler-78b’s days are numbered. The extreme gravitational pull from its star will draw it ever closer in, ripping the entire planet apart in about three billion years.

But because this blast was 3.7 billion light-years away, mankind was spared. In fact, no one on Earth could even see it with the naked eye.

A gamma ray burst happens when a massive star dies, collapses into a brand-new black hole, explodes in what's called a supernova and ejects energetic radiation. The radiation is as bright as can be as it travels across the universe at the speed of light.

A planet caught in one of these bursts would lose its atmosphere instantly and would be left a burnt cinder, astronomers say.

Scientists might be able to detect warning signs of an impending gamma ray burst. But if a burst were headed for Earth — and the chances of that happening are close to zero, astronomers say — there wouldn't be anything anybody could do about it.

NASA telescopes in orbit have been seeing bursts for more than two decades, spotting one every couple of days. But this one, witnessed on April 27, set records, according to four studies published Thursday in the journal Science.

It flooded NASA instruments with five times the energy of its nearest competitor, a 1999 blast, said University of Alabama at Huntsville astrophysicist Rob Preece, author of one of the studies.

It started with a star that had 20 to 30 times the mass of our sun but was only a couple of times wider, so it was incredibly dense. It exploded in a certain violent way.

In general, gamma ray bursts are "the most titanic explosions in the universe," and this one was so big that some of the telescope instruments hit their peak, Preece said. It was far stronger and lasted longer than previous ones.

"I call it the monster," Preece said. In fact, one of the other studies, not written by Preece, used the word "monster" in its title, unusual language for a scientific report.

One of the main reasons this was so bright was that relative to the thousands of other gamma ray bursts astronomers have seen, the monster was pretty close by cosmic standards. A light-year is almost 6 trillion miles.

Most of the bursts NASA telescopes have seen have been twice as distant as this one. Other explosions could be this big, but they are so much farther away, they don't seem so bright when they reach Earth, the studies' authors say.

Astronomers say it is incredibly unlikely that a gamma ray burst — especially a big one like this — could go off in our galaxy, near us. Harvard's Avi Loeb, who wasn't part of the studies, put the chances at less than 1 in 10 million.

Our galaxy doesn't have many of the type of star that lends itself to gamma ray bursts, said Charles Dermer, a co-author of the studies and an astrophysicist at the U.S. Naval Research Laboratory.

"The chance of anything happening and being dangerous is virtually nil," Dermer said.

Also, because a burst is concentrated like a focused searchlight or a death beam, it has to be pointing at you to be seen and to be dangerous.

"Either it's pointed at us or it's not," Preece said. "If it's not, yay! Civilization survives and we see maybe a supernova. If it were pointed at us, then it matters very much how far away it is in our galaxy. If it's in our local arm, well, we had a good run."

Some theorize that a mass extinction on Earth 450 million years ago was caused by a gamma ray burst in a nearby part of our galaxy, but Dermer said that's unlikely.

We don't see gamma ray bursts from the surface of Earth because the atmosphere obscures them and because most of their light is the type we cannot see with our eyes. That's why NASA has satellites that look for them.

This burst was so bright telescopes on Earth saw a brief flash in the constellation Leo.

For scientists, this was a wow moment.

"These are really neat explosions," said Peter Michelson, a Stanford physicist who is the chief scientist for one of the instruments on a NASA gamma ray burst-spotting telescope. "If you like fireworks, you can't beat these. Other than the Big Bang itself, these are the biggest there are."

The burst "is part of the cycle of birth and life and death in the universe," Michelson said. "You and I are made of the stuff that came from a supernova."

NASA’s Juno spacecraft captured this amazing video of the Moon orbiting Earth as it passed by our planet on October 19th, 2013. Using a camera designed to track faint stars, Juno captured the images — which were later assembled into a video — at a distance of about 600,000 miles. As it passed by Earth, the spacecraft accelerated to more than 8,800 mph in order to reach Jupiter by July 4th, 2016.

I wish man would put billions into our own planets survival vs looking at other planets we can move to and destroy. Not to mention I am of the opinion that it is mathematically impossible for us to be the only ones and what if we are "putting up flares" for others to discover us. Others who may have wrecked their planet and are looking for resources. We assume other beings are going to be peaceful.

Religion and astronomy may not overlap often, but a new NASA X-ray image captures a celestial object that resembles the "Hand of God."

The cosmic "hand of God" photo was produced when a star exploded and ejected an enormous cloud of material, which NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, glimpsed in high-energy X-rays, shown in blue in the photo. NASA's Chandra X-ray Observatory had imaged the green and red parts previously, using lower-energy X-rays.

"NuSTAR's unique viewpoint, in seeing the highest-energy X-rays, is showing us well-studied objects and regions in a whole new light," NuSTAR telescope principal investigator Fiona Harrison, of the California Institute of Technology in Pasadena, said in a statement.

The new image depicts a pulsar wind nebula, produced by the dense remnant of a star that exploded in a supernova. What's left behind is a pulsar, called PSR B1509-58 (B1509 for short), which spins around 7 times per second blowing a wind of particles into material ejected during the star's death throes.

As these particles interact with nearby magnetic fields, they produce an X-ray glow in the shape of a hand. (The pulsar is located near the bright white spot in the image but cannot be seen itself, NASA officials said.)

Scientists aren't sure whether the ejected material actually assumes the shape of a hand, or whether its interaction with the pulsar's particles is just making it appear that way.

"We don't know if the hand shape is an optical illusion," Hongjun An, of McGill University in Montreal, said in a statement. "With NuSTAR, the hand looks more like a fist, which is giving us some clues."

The red cloud appearing at the fingertips is a separate structure called RCW 89. The pulsar's wind may be heating the cloud to produce the low-energy X-ray glow, astronomers believe.

The X-ray energies seen by NuSTAR range from 7 to 25 kiloelectron volts, or keV, whereas the energies seen by Chandra range from 0.5 to 2 keV.

The Hand of God is an example of pareidolia, the psychological phenomenon of perceiving familiar shapes in random or vague images. Other common forms of pareidolia include seeing animals or faces in clouds, or the man in the moon. Despite its supernatural appearance, the Hand of God was produced by natural astrophysical phenomena.

October 14, 2012, Felix Baumgartner ascended more than 24 miles above Earth's surface to the edge of space in a stratospheric balloon. Millions across the globe watched as he opened the door of the capsule, stepped off the platform, and broke the speed of sound while free falling safely back to Earth. Felix set three world records that day—and inspired us all to reach beyond the limits of our own realities, and reimagine our potential to achieve the incredible.

GoPro was honored to be a part of this epic achievement, with seven HERO2 cameras documenting every moment. From the airless freeze of outer space, to the record-breaking free fall and momentous return to ground—see it all through Felix's eyes as captured by GoPro, and experience this incredible mission like never before. No one gets you closer than this.

Move a few astronomical units over, Pluto, there’s a new dwarf in town. Astronomers have announced in Nature that they’ve discovered a new dwarf planet which, at its closest, passes about 7.2 billion miles from the sun. And what’s more, the apparent movement of this new planetoid hints that a much larger planet could be orbiting even farther out, one that could be 20x bigger than Earth.

The new body has been dubbed 2012 VP-113 and measures about 280-miles across. Circling our sun at a minimum of 80 astronomical units (1 au = the distance between the earth and the sun), 2012 VP-113 is well beyond the Kuiper belt, a thick ring of frozen bodies which orbits beyond Neptune (the farthest planet out) at 30 to 55 au away.

While 2012 VP-113 is officially way the hell out there, it’s still not as far out as the Oort cloud – a massive expanse of icy material stretching from 50,000 to 100,000 au away. To give you a sense of how far that is, a light year is equivalent to a mere 63,240 au. If the Oort cloud hurts your brain too much to think about, you can hold out hope that its existence gets debunked someday – the concept is still just a hypothesis.

It was long thought that the area between the Kuiper belt and the Oort cloud was entirely featureless, but this notion changed with the 2003 discovery of the 600 mile wide dwarf planet Sedna. The presence of this relatively large body in this supposedly vacant region made astronomers wonder what else might be out there. Even for super smart scientists with super powerful telescopes, seeing small stuff that’s really far away is still super hard. To spot more planetoids like Sedna they’d have to detect faint beams of light that manage to reach these distant worlds, reflect off of them, and then bounce all the way back to us. To accomplish such a feat, astronomers enlisted what has to be the most bad-ass sounding scientific instrument in the game, the Dark Energy Camera on the NOAO 4-meter telescope in Chile. Finally they spotted the faint, dim object they’ve now dubbed 2012 VP-113

Here’s what’s getting scientists (and us) really excited. Sedna and 2012 VP-113 seem to be making their tightest approach to the sun at similar angles, and this could mean that they are being affected by the gravity of a much larger body. If this planet exists, scientists suspect this giant could be up to 20x bigger than Earth. Only time – and the discovery of more dwarf planets like these – will tell if there’s a monster lurking beyond the Kuiper belt.

What do you think, Nerdist science readers? Is there a distant mega ice planet out there affecting the orbits of Sedna and 2012 VP-2013? And more importantly, could it be Hoth!?

The First Total Lunar Eclipse of 2014 Will Be Visible Tonight In North and South America

Residents of North and South America will get a chance to see the year’s first total lunar eclipse late tonight / early tomorrow. The celestial event will begins at 0600 GMT (2AM ET, 11PM PT) and will last around 3.5 hours. The Earth’s shadow on the moon will cause the lunar surface to appear as a burnt red color, one of four such occurrences set for the next year and a half, with the next one happening October 8th, 2014. For anyone not in viewing range or expecting bad weather, Space.com will feature a live webcast of the event.

For those who were unable to view the “blood moon” lunar eclipse on April 14, 2014 due to global positioning, weather or timing, TIME has condensed the whole event into a nine-second animated GIF. Of particular note is the brief reddish hue caused by light refracted by the Earth’s atmosphere.

Scientists say a world that's 490 light-years away qualifies as the first confirmed Earth-sized exoplanet that could sustain life as we know it — but in an environment like nothing we've ever seen.

The planet, known as Kepler-186f, is "more of an Earth cousin than an Earth twin," Elisa Quintana, an astronomer at the SETI Institute at NASA Ames Research Center, told the journal Science. Quintana is the lead author of a report on the planet published by Science this week.

"This discovery does confirm that Earth-sized planets do exist in the habitable zones of other stars," Quintana said during a Thursday news briefing at NASA Headquarters.

Kepler-186f goes around an M-type dwarf star that's smaller and cooler than our sun. But it orbits much closer to its parent star than Earth does, within what would be Mercury's orbit in our own solar system. Those two factors combine to produce an environment that could allow for liquid water on the surface, assuming that the planet had a heat-trapping atmosphere.

"The star, to our eyes, would look slightly orange-y," about a third again as big as our sun but only a third as bright, said co-author Thomas Barclay, a staff scientist for NASA's Kepler mission who is also affiliated with NASA and the Bay Area Environmental Research Institute. At midday, Kepler-186f's landscape might look similar to what we see on Earth an hour before sunset, he told NBC News.

Or it might not: If the planet lacked an atmosphere to retain and redistribute its sun's warmth, it would be a cold, dry, lifeless world.

Kepler-186f probably rates as the most potentially Earthlike planet discovered so far, said Jim Kasting, a geoscientist at Penn State University who did not play a role in the Science study. But he told NBC News that it's still "less likely to be habitable than planets around more sunlike stars." Even better prospects for alien habitability might well be identified in the months and years to come.

How the world was found

Kepler-186f is just the latest discovery to be pulled out of terabytes' worth of data collected by the Kepler mission. Before it went on the fritz last year, the Kepler space telescope stared at more than 150,000 stars in a patch of sky, looking for the telltale dimming of starlight as planets passed over the stars' disks. Nearly 1,000 exoplanets have been confirmed using Kepler data, and almost 3,000 more candidates are still awaiting confirmation.

It takes years of observation to confirm the pattern of dimming and brightening that's associated with alien planets, particularly if the planets are small and far from their parent stars. In February, astronomers reported that at least four worlds circled the dwarf star known as Kepler-186 or KOI-571. In this week's Science paper, Quintana and her colleagues confirm the existence of Kepler-186f as the fifth and outermost world.

They report that Kepler-186f is about 10 percent wider than Earth, tracing a 130-day orbit around its sun at a mean distance of 0.35 astronomical units. (An astronomical unit is the distance between Earth and our sun, which is 93 million miles or 150 million kilometers.) That would put Kepler-186f on the cooler, outer side of the star's habitable zone — the range of orbital distances where liquid water could exist on a planet's surface.

Astronomers have confirmed the existence of other planets in their stars' habitable zone, but those prospects are super-Earth-size. Smaller habitable-zone candidates also have been found, but they have yet to be confirmed as planets.

Barclay said Kepler-186f was particularly promising because it's less than 1.5 times the size of Earth. Planets in that size range are more likely to be rocky with a thinner atmosphere, like Earth, Mars and Venus. But worlds exceeding that size stand a better chance of retaining a thick atmosphere of hydrogen and helium, like the giant planet Neptune.

"While those planets also could be rocky, they don't remind us of home," Barclay said.

M-dwarf stars are thought to be the most numerous stars, accounting for as much as 70 percent of the stars in the Milky Way. As a result, "the first signs of other life in the galaxy may well come from planets orbiting an M dwarf," Quintana said.

The promise of worlds to come

Could we actually detect signs of life on Kepler-186f? That's a tough one. The astronomers behind the discovery acknowledge that the planet might be just too far away for follow-up studies. The SETI Institute has been searching for radio signals from the Kepler-186 system over a wide frequency range (1 to 10 GHz), but so far nothing has been detected.

Kasting, the author of "How to Find a Habitable Planet," said worlds around M-class dwarf stars faced several disadvantages in the habitability department. For one thing, such planets generally end up being tidally locked to their stars — meaning that one side of the planet is always facing its parent sun while the other is always turned away. "This is not a show-stopper for habitability, but it's a problem nonetheless," Kasting said.

Also, M-class stars tend to throw off strong stellar winds and flares that could blast away a planet's atmosphere. In Kasting's view, the most serious problem is that such stars are thought to glow much brighter early in their lifetime, and only later settle down to become dimmer than the sun.

"Thus, a planet like Kepler 186f that is within the star's habitable zone today may have been strongly heated soon after it formed, in which case it may have lost its water early by way of a runaway greenhouse," Kasting said in an email.

These are the reasons why astronomers are so interested in searching for Earth-sized planets that lie in the habitable zones around stars that are more like our sun. "We just need a lot of money and political will to do that," Kasting said.

Further analysis of the data from Kepler could produce those prospects, but scientists are also banking on future missions such as NASA's Transiting Exoplanet Survey Satellite and James Webb Space Telescope, the European Space Agency's PLATO and CHEOPS probes, and the Giant Magellan Telescope in Chile. Such observing instruments could look for the potential signatures of life in alien atmospheres.

Scientists say a world that's 490 light-years away qualifies as the first confirmed Earth-sized exoplanet that could sustain life as we know it — but in an environment like nothing we've ever seen.

The planet, known as Kepler-186f, is "more of an Earth cousin than an Earth twin," Elisa Quintana, an astronomer at the SETI Institute at NASA Ames Research Center, told the journal Science. Quintana is the lead author of a report on the planet published by Science this week.

"This discovery does confirm that Earth-sized planets do exist in the habitable zones of other stars," Quintana said during a Thursday news briefing at NASA Headquarters.

Kepler-186f goes around an M-type dwarf star that's smaller and cooler than our sun. But it orbits much closer to its parent star than Earth does, within what would be Mercury's orbit in our own solar system. Those two factors combine to produce an environment that could allow for liquid water on the surface, assuming that the planet had a heat-trapping atmosphere.

"The star, to our eyes, would look slightly orange-y," about a third again as big as our sun but only a third as bright, said co-author Thomas Barclay, a staff scientist for NASA's Kepler mission who is also affiliated with NASA and the Bay Area Environmental Research Institute. At midday, Kepler-186f's landscape might look similar to what we see on Earth an hour before sunset, he told NBC News.

Or it might not: If the planet lacked an atmosphere to retain and redistribute its sun's warmth, it would be a cold, dry, lifeless world.

Kepler-186f probably rates as the most potentially Earthlike planet discovered so far, said Jim Kasting, a geoscientist at Penn State University who did not play a role in the Science study. But he told NBC News that it's still "less likely to be habitable than planets around more sunlike stars." Even better prospects for alien habitability might well be identified in the months and years to come.

How the world was found

Kepler-186f is just the latest discovery to be pulled out of terabytes' worth of data collected by the Kepler mission. Before it went on the fritz last year, the Kepler space telescope stared at more than 150,000 stars in a patch of sky, looking for the telltale dimming of starlight as planets passed over the stars' disks. Nearly 1,000 exoplanets have been confirmed using Kepler data, and almost 3,000 more candidates are still awaiting confirmation.

It takes years of observation to confirm the pattern of dimming and brightening that's associated with alien planets, particularly if the planets are small and far from their parent stars. In February, astronomers reported that at least four worlds circled the dwarf star known as Kepler-186 or KOI-571. In this week's Science paper, Quintana and her colleagues confirm the existence of Kepler-186f as the fifth and outermost world.

They report that Kepler-186f is about 10 percent wider than Earth, tracing a 130-day orbit around its sun at a mean distance of 0.35 astronomical units. (An astronomical unit is the distance between Earth and our sun, which is 93 million miles or 150 million kilometers.) That would put Kepler-186f on the cooler, outer side of the star's habitable zone — the range of orbital distances where liquid water could exist on a planet's surface.

Astronomers have confirmed the existence of other planets in their stars' habitable zone, but those prospects are super-Earth-size. Smaller habitable-zone candidates also have been found, but they have yet to be confirmed as planets.

Barclay said Kepler-186f was particularly promising because it's less than 1.5 times the size of Earth. Planets in that size range are more likely to be rocky with a thinner atmosphere, like Earth, Mars and Venus. But worlds exceeding that size stand a better chance of retaining a thick atmosphere of hydrogen and helium, like the giant planet Neptune.

"While those planets also could be rocky, they don't remind us of home," Barclay said.

M-dwarf stars are thought to be the most numerous stars, accounting for as much as 70 percent of the stars in the Milky Way. As a result, "the first signs of other life in the galaxy may well come from planets orbiting an M dwarf," Quintana said.

The promise of worlds to come

Could we actually detect signs of life on Kepler-186f? That's a tough one. The astronomers behind the discovery acknowledge that the planet might be just too far away for follow-up studies. The SETI Institute has been searching for radio signals from the Kepler-186 system over a wide frequency range (1 to 10 GHz), but so far nothing has been detected.

Kasting, the author of "How to Find a Habitable Planet," said worlds around M-class dwarf stars faced several disadvantages in the habitability department. For one thing, such planets generally end up being tidally locked to their stars — meaning that one side of the planet is always facing its parent sun while the other is always turned away. "This is not a show-stopper for habitability, but it's a problem nonetheless," Kasting said.

Also, M-class stars tend to throw off strong stellar winds and flares that could blast away a planet's atmosphere. In Kasting's view, the most serious problem is that such stars are thought to glow much brighter early in their lifetime, and only later settle down to become dimmer than the sun.

"Thus, a planet like Kepler 186f that is within the star's habitable zone today may have been strongly heated soon after it formed, in which case it may have lost its water early by way of a runaway greenhouse," Kasting said in an email.

These are the reasons why astronomers are so interested in searching for Earth-sized planets that lie in the habitable zones around stars that are more like our sun. "We just need a lot of money and political will to do that," Kasting said.

Further analysis of the data from Kepler could produce those prospects, but scientists are also banking on future missions such as NASA's Transiting Exoplanet Survey Satellite and James Webb Space Telescope, the European Space Agency's PLATO and CHEOPS probes, and the Giant Magellan Telescope in Chile. Such observing instruments could look for the potential signatures of life in alien atmospheres.

This is really great, wish we could contact them.

How do we know it's there if it takes 409 light years (right?) for light to travel from there? What we're seeing when we look at the light that shines from the star over the planet is from 409 years ago?

Last week, we learned that the Great Red Spot of Jupiter–a massive storm swirling on the planet for centuries–is getting much less great. But why?

The Space Telescope Science Institute will be having a “Hubble Hangout” tomorrow at 1 p.m. PDT to discuss this finding with actual scientists on the Hubble team. Science communicator and space enthusiast Scott Lewis will be co-hosting with Tony Darnell–one of the social media managers of STScI–and speaking with scientists Carol Christian and Amy Simon.

The hangout will use the Q&A app (available on YouTube and Google+) to field questions from the audience, and will respond to Twitter (#HubbleHangout), YouTube, and G+ comments.

The live-stream of the hangout is featured below and will go live when the hangout starts: